Add support for block override in eth_call

[fvictorio]

See docs here: https://geth.ethereum.org/docs/interacting-with-geth/rpc/ns-eth#eth-call

The fields to support are:

• number
• difficulty
• time
• gasLimit
• coinbase
• random
• baseFee
• blobBaseFee

Integration tests for this are relatively easy to implement. We just need to deploy a contract like this:

contract BlockOverrideTest {
  function getBlockNumber() public view returns (uint) {
    return block.number;
  }

  function getBlockTimestamp() public view returns (uint) {
    return block.timestamp;
  }

  // etc.
}

and call each function with the proper override. (Testing that multiple things can be overridden with a single call is a bit more involved, but still doable.)